Electrolytic condenser



, 1,703,630 H. N. MILLER v ELCTROLYTI CONDENSER Filed April 9, 1927 l 2 ShGGtS-Sheei l2 Patented Feb. 26,1929. i

UNITED w STATES 1,703,680 PATENT OFFICE.

HARRY N. MILLER, OF CHICAGO, ILLINOIS, ASSIGNOR TO FANSTEEL PRODUCTS COM- PANY, INC., OF NORTH CHICAGO, ILLINOIS, A CORPORATION F NEW YORK.

ELECTROLYYTIC CONDENSER.

Application led April 9, 1927. Serial No. 182,302.

This invention relates to an electrolytic condenser of the type described in my copending application, Serial No. 17 3,031, filed- March 5, 1927. It relates, more particularly,

to a unit comprising condenser cells, each of which is composed of filmed plates and conductive plates separated by insulating rivets and immersed in an electrolytegel prepared by incorporating an electrolyte in a solution of gelatin in glycerin.

The object of my invention is to provide an improved electrolytic condenser.

Other objects will be apparent from the detailed description.

` In the accompanying drawings which repv resent a preferred embodiment of myv invention,

Fig. 1 is a vertical section of my improved condenser, taken on lines 1`1 of Figs. 2

2o and 3. r U

Fig. 2 is a vertical section on lines 2-2 of Figs. 1 and 3.

Fig. 3 is a horizontal section taken on line 3 of Figs. 1 and 2.

Fig. 4 is a plan; of the conductive plate showing the arrangement of the insulating rivets.

Fig. 5 is a horizontal section of said plate on lines 5-5 of Fig. 4.

Fig. 6 is a plan of the aluminum plate.

Fig. 7 shows the individual-cell container, and

Fig. 8 is a perspective view of the finished condenser. i

In the several figures, similar parts are referred to by like reference characters.

In various lter circuits, such las are used for eliminating the pulsations in rectified alternating current, a number of condensers of high capacity are required. Electrolytic condensers have proven very satisfactory in that a large capacity may be obtained 1n a smaller volume than with the corresponding dry condensers. However, the electrolyte, in

the Huid state, has been objectionable, due to its corrosive efect and due to the inconvenience in handling it. By incorporating the electrolyte in a gel, I have found that the high capacity can' be obtained without these 5o objectionable features. v

. The specific example described here is designed to be used with direct pulsating current. When a voltage is impressed on the filmed aluminum plate, the cell acts as a condenser but when the voltage decreases, the

discharge of this condenser is in the form of a smooth curve-and not an oscillating wave because the cell does not .function as a condenser when a voltage is impressed on the negative plate.

A receptacle 1, preferably of stamped sheet metal, is provided with a series of apertures `in one side, as shown in Fig. 8. A n'umber of containers 11, 12, 13 and 14 are placed in the receptacle, as shown in Figs. 2 andl 3. 65 Each of these containers is composed of insulating material, such as hard rubber, cardboard or Vthe like, and if a fibrous material, such as cardboard, is used the container is impregnated with a waterproof material, such as paraffin.

The condenser plates are preferably aluminum and iron, although any suitable valve metal may be used instead of aluminum, and any conductor or conductive metal may take the place of iron. The preferred shapes of the sheets or plates are shown in Figs. 4 to 6.

Fig. 4 shows an iron plate provided with va tab 15 vand with five holes 17 arranged as shown in the drawing. Into each of these so holes is fixed an insulating rivet 18, the ends of which protrude from the 'plate about 131g to lg of an inch. The aluminum plates preferably have the tab 16 at the edge instead of in the center. The aluminum plates are filmed in a saturated solution of sodium bicarbonate with a direct current otential of about 250 volts and, when d rie are alternately arranged with the iron platesin the container 11.

An electrolyte 19 is prepared by heating 1 part of gelatin with 5 or 6 parts of glycerin on a water bath until the gelatin is dissolved, saturating this solution with sodium bicarbonate and adding a, small amount of lithium hydroxide. This electrolyte is then poured between and around plates 13 and 14 in the container.

Cells 11 and 12 are shown with two plates, one of aluminum and one of iron. Cells 13 100 and 14 are shown as including four plates, two of aluminum and two of iron. It is understood, of course, that various numbers of cells and various numbers of plates per cell maybe used, as the requirements of any particular use may demand.

Suitable wiring connections are shown in Figs. 2 and 3. All of the iron plates-are connected by conductors 20 which are, in turn, connected to a lead out Wire 21. A wire 11o 22 is connected to the tab 16 of the aluminum plate in cell 11 and this wire is led out from one of the openings 25, as shown in Fig. 8.

In a like manner the aluminum plate of cell 12 is connected to lead outl wire 22'.; The

spective capacity of the condenser to which` it is connected. For example, agreen wire may lndlcate connectlon to a two-plate condenser, red insulation to a four-plate condenser, white insulation to a -sixfplate condenser, etc., the negative lead of each condenser being represented by black'insulation on the wire 21.

Since a common lead out wire is used for all condenser cells in the unit, it is important that the containers of each cell be good insulators and that they be waterproof for reasons which are deemed obvious.

` When the units are in place and the Wires are connected as above described, molten paraiin 24 is poured over the cells, a strip of paper 25 is placed over the paraffin and a wax seal 26 is applied. If the wax seal is poured directly onto the paraliin the finish is not as satisfactory because some of the paraliin melts and comes to the surface of the wax.

It will be seen that I have provided a compact unit comprising a series of electrolytic condensers that will lind wide application in' filter circuits. The electrolyte is in a nonfluid state under normal operating conditions but, should the cell become heated,rno damage will result because the insulating rivets will keep the plates from short circuiting. Should the voltage be accidentally raised to too high a point and the film become punctured, the electrolyte will reform the film. Since no appreciable current flows there will be no gassing. The tacky quality of the gel assures constant adhesion to the surfaces of the plates.

A condenser unit of the typeY described is waterproof container, a filmed aluminum plate, an iron plate, insulating means for keeping the plates in intimately spaced relation under all operating conditions, and an electrolyte comprising sodium bicarbonate,

in a dry gelatin-glycerin gel.

2. `An electrolytic unit comprising a plurality of receptacles, each includin a filmed electrode and a non-filmed electro e, a lead for electrically connecting the non-filmed electrodes together, separate leads' to the filmed electrodes in the separate receptacles, and an ionogen incorporated in a dry glycerin composition in each of the receptacles.

3. A condenser unit'k comprising a plurality of filmed electrodes, separate receptacles adapted to contain said electrodes, a substantially -dry electrolyte in each receptacle, a common conductor leading to the electrolyte in the several receptacles and individual conductors leading to the several filmed electrodes.

4. In a Water-proof electrolytic condenser a lmed aluminum electrode, a conductive electrode, insulating means for keeping the electrodes in intimately spaced relation under all operating conditions, and an electrolyte comprising a substantially dry solution of an ionogen in glycerin. I

In witness whereof, I hereunto subscribe my name this 6 day of April, 1927.

HARRY N. MILLER.v 

